In the case of such light curing devices, it is known to use optical means, including a reflector and/or a converging lens, to focus the light beam emitted by a light source. Such light curing devices are used for example for the light curing or polymerization of dental materials, the light beam emerging from the light curing device then being directed to the dental restoration part that is to be polymerized.
Dental restoration parts may take a wide variety of forms, and the regions of a tooth that are to be polymerized may be mesial or distal. Especially when they are distal, directing the amount of light required to cure them fully often causes problems. To facilitate this, it has become known to bend away the end of the light guide of the light curing device transmitting the light beam. An example of this is the light curing device known from DE 42 11 230.
Light curing devices of a substantially pistol-like form have proven to be essentially successful, since they make targeted work possible. On the other hand, they are comparatively heavy, in particular if they also hold storage batteries for the power supply.
Furthermore, it has also already been considered to produce stick-like light curing devices in which the light guiding stick is bent away, for example by 45°. In this respect, reference is made for example to DE 101 44 414 A1.
For optimum full curing of the dental restoration part that is to be polymerized, it is important to line up the light exiting direction with the position of the dental restoration part. If, for example, a light curing device with a bent-away light guiding stick, and accordingly a light exiting area extending obliquely in relation to the axis of the light curing device, is held obliquely in relation to the surface of the dental restoration part on the latter, the light energy emitted is typically concentrated only on part of the dental restoration part. This has the effect that the dental restoration part is intensively cured fully on one side, but not on the other side, so that free radicals may remain there.
Although it has been proposed in connection with the detection of decay to use an oblique light exiting area deliberately, in order to promote better decay detection, such a solution is extremely poor for light curing devices.
Furthermore, it has also already become known to fit an attachment onto the end of the light guiding stick and bring about a deflection of the light in this way. In this respect, reference is made to DE 101 24 367 A1.
Furthermore, it is known from DE 32 33 410 A1 to use a light curing device with a flexible light guide, it being possible for the light guide itself to be modified with scissors or a knife or slightly melted with a flame.
This is intended to make the light exit variable. However, a disadvantage here is that, with cut-off light guides, the optical quality is usually poor, especially when inexpensive plastic light guides are used. If the light guide is quite simply cut off obliquely, the light is radiated over a wide angle with low light intensity. Melting also has the effect here that there is only limited focusing, again generally stopping the light emission in the oblique direction.